BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Brown-headed Cowbird In Northern Rockies

All regionsNorthern RockiesGeneralists

Brown-headed Cowbird in Northern Rockies has increased: up 42% on the route-weighted index since 1970.

+42%Since 1970
220Routes In Region
56Years

Notable Signals

No notable trend signals for Brown-headed Cowbird in Northern Rockies. See the full index history below.

Forecast

If the recent trend holds, Brown-headed Cowbird in Northern Rockies is projected to rise about 60% by 2029 — from 4.3 in 2024 to a central estimate of 6.9 (95% range 3.5–10). A 5-year backtest shows a typical error of ±73.6%, with 40% of held-out values landing inside the 95% band.

+60%Change by 2029
6.9Projected 2029 index
3.5–1095% range
±73.6%Backtest error
19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20256.83.410
20266.83.510
20276.83.510
20286.83.510
20296.93.510

Routes In Northern Rockies

Routes recording Brown-headed Cowbird in Northern Rockies.
CascadeIDAHO551984
AugustaMONTANA362024
WoodruffUTAH272024
St MaryMONTANA252008
MidvaleWYOMING252022
Wolf CreekMONTANA212022
RaynesfordMONTANA212024
SpartaOREGON202001
RandolphUTAH202024
CabartonIDAHO182023
BoulderMONTANA172024
Muddy CreekMONTANA172015
Clyde ParkMONTANA142024
Silver CreekOREGON142024
NewbridgeOREGON142024
PolsonMONTANA132024
Pablo Res.MONTANA132024
Deer ParkWASHINGTON132015
Church HillMONTANA122024
Hebgen LakeMONTANA122024
Rock RiverWYOMING122022
Mount VernonOREGON112024
Hayden ValWYOMING111986
KalispellMONTANA102024
Red RockMONTANA102024

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.